There is a lack of information on sperm-specific antigens, especially in the human. It is the objective of the proposed investigation to fractionate soluble and solubilized components of human and rhesus monkey spermatozoa, primarily surface and acrosomal components, and to thereby isolate and characterize antigens that show cyto-(tissue) specificity. Heteroantisera will be used as a tool to monitor these procedures and to establish cyto-(tissue) specificity by tissue homogenate absorption procedures. The comparative studies between human and rhesus monkey spermatozoa will provide information on biochemical and immunological similarities of analogous antigens. This information is essential for meaningful investigations into the iso-immunogenicity of such sperm-specific antigens in female rhesus monkeys. This work cannot be done in humans. The results of such studies will contribute to a critical evaluation of the feasibility and desirability of immunological fertility regulation based on interference with sperm transport and fertilization. The isolation of human sperm-specific antigens will also facilitate the development of better techniques for the diagnosis of clinical immunological infertility and of the sequelae of vasectomy.